PPRuNe Forums - View Single Post - MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Old 24th Jun 2019, 03:29
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mattler
 
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yoko1: I get what you're saying, and it's absolutely correct. I just don't think that it's the whole picture. And unfortunately, we don't have the information required to assemble the whole picture.

It seems like people are using the term "anti stall device" to imply that MCAS has a similar function to alpha prot/floor from the Airbus. So is MCAS that kind of a system? According to Boeing, no. But according to two Boeing engineers that I have been speaking with with, possibly yes. They assert that the data that they saw strongly suggested instability at high AOA and poor stall characteristics, leading us to believe that 737 MAX has stall issues. Nader asserts this too, and regardless of what one thinks about him, we can bet that he's got better info than most of us. He has been speaking with numerous whistleblowers.

Here is a direct quote from a Boeing engineer whom I trust, and who shall remain nameless despite recently retiring. His last sentence is chilling:

"I recall seeing the Cl and Cm Alpha for the MAX from the transonic test and it didn't look good. I retired shortly after that so don't know how it went from there [...] Boeing can claim it was just trying to standardize stick feel but the bottom line is that it did not meet FAA requirements for stability. I would hope that the lift and moment curves would be made public along with the results of the certification flight test. That's the only way I would feel comfortable flying on a MAX."

It seems like the issue between you, and those who disagree with you, is that we don't actually have all of the information yet. We desperately need to see the relevant data before we can assess what MCAS is, or is not. And we need to have this settled before the aircraft is once again cleared for flight.
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